Method and apparatus for winding coils automatically and coil strings derived therefrom



April 14, 1964 c. LIEBMAN 3 128,798

METHOD AND APPARATUS FOR Filed July 18, 1958 WINDING COILS AUTOMATICALLY AND COIL STRINGS DERIVED THEREFROM 2 Sheets-Sheet 1 84 Cvwnes L S S BY H] ATTOR. may

April 1964- c. LIEBMAN 3,128,798

' METHOD AND APPARATUS FOR WINDING COILS AUTOMATICALLY AND COIL STRINGS DERIVED THEREFROM 2 Sheets-Sheet 2 Filed July 18, 1958 aya C HAELE 5 l uss N ATTORNEY United States Patent Office 3,128,798 Patented Apr. 14., 1964 3,123,798 METHOD AND APPARATUS FOR WINDHQG COHLS AUTOMATICALLY AND CUIL STRINGS DE- RIVED THEREFROM Charles Liebrnan, Rte. 3, Mcfienry, Ill. Filed July 18, 1958, Ser. No. 749,499 3 Claims. (Cl. Mil-92.2)

My invention relates to an automatic coil winder, to a method of winding coils automatically and to the coils as so wound.

In conventional commercial coil winding, a coil winding machine is employed which consists of a rotating mandrel, a revolution counter, a wire supply and a needle which receives wire from the wire supply and lays it on the mandrel. In some applications the wire passes through a bath to make it tacky immediately before winding so that the turns of the wound coil will stick together and the coil thus be cemented together to maintain its form. The bath may contain a fast drying plastic solution which is tacky when Wet or Wire having an insulating coating thereon which is soluble in a fast drying solvent may be passed through the solvent to make the insulation sufiiciently tacky so that the coil turns will cohere together. The latter is the most commonly used practice and acetone is the material employed to make sticky the insulating composition.

Under existing practice a winding machine operator places a few turns of wire on the mandrel leaving an unwound length at the end thereof for circuit connection, then operates the winder While watching the revolution counter until the desired number of turns have been placed on the mandrel. The wire is then snipped off a short distance from the coil so as to leave a length at the other end thereof for circuit connection. This process requires constant attention, as will be appreciated. An operator is required at each machine to start each coil, count the number of turns and disconnect the finished coil from the mandrel and from the wire supply. Where coils are to be formed having large number of turns so that appreciable time is allowed for the winding process, it is conceivable that one operator may attend more than just one machine but the coils most commonly encoun tered in the radio and television industry are not such as to permit this divided attention on the part of a machine operator.

A primary object of my invention is the provision of a method for coil winding whereby coils may be Wound completely automatically without the need for human manipulation between the winding of successive coils. Another object of my invention is the provision of mechanism of an accessory nature attachable to conventional coil winding machines to adapt the machines for the automatic winding of coils. Still another object of my invention is the provision of a coil winding machine adapted for the continuous and automatic production of coils. The mechanism by which I obtain automatic coil production from a coil winding machine is simple, inexpensive, sure in operation and delivers coils generally superior in accuracy as to the number of turns to those wound by presently practiced procedures.

As coils are produced in the practice of my novel method or by the employment of my novel mechanism, the consecutive coils emerge from the process as discrete coil bodies intreconnected by single strands of the wire of which the coil is formed. Although my process at first view seems to call for a severing of the coils one from the other, upon handling of the coils for assembly, for shipping, for inspection or counting, I have found that a plurality of coils connected together by the aforesaid single strands of Wire possess definite and substantial manipulative advantage over coils detached from one another. A still further object of my invention, therefore, is the provision of a plurality of coils connected one to another by lengths of the wire of which the coil is formed.

Other objects and advantages of my invention will be apparent from the following description and drawings of which:

FIG. 1 is a top plan view of a coil winding machine of the universal type adapted for the automatic production of coils;

FIG. 2 is a front elevation of the machine of FIG. 1;

FIG. 3 is a view taken substantially along the line 3-3 of FIG. 2 looking in the direction of the arrows;

FIG. 4 is a rear elevation of the gear box of the coil winder of FIG. 1;

FIG. 5 is a front elevation of the ejector clamp of my invention;

FIG. 6 is a side elevation of the ejector sleeve;

FIG. 7 is a side elevation of the ejector clamp and sleeve assembled;

FIG. 8 is a side elevation of the winding machine, mandrel and extension; and

FIGS. 9, 10 and 11 are rear side elevations of the winding parts of the coil winder of my invention illustrating consecutive stages in the ejection of a coil.

Although my invention and the method involved therein is applicable to any coil winding machine which employs a rotating mandrel on which the coil is formed, I have illustrated it in conjunction with a universal winding machine or that type of machine producing universally wound coils. I

In FIG. 1 is illustrated a coil Winding machine 10 of the universal type which includes a transmission box 12 having a pulley shaft 14 and pulley 16 extending from one side thereof and a drive shaft 18 extending from the other side thereof. The rear side of the transmission box has mounted thereto a counter gear train 20 and the front side of the box incorporates the winding needle oscillating mechanism indicated generally by number 22. This mechanism includes a shaft 24 extending out from the front of the box and powered through appropriate gearing by the pulley shaft 14. The rate of rotation of shaft 24 relative to the rotation of the pulley shaft 14 may be adjusted by the introduction of appropriate idlers into the gear train (not shown) which drives shaft 24. This mechanism is entirely conventional and plays no part in my invention and illustration is, therefore, believed unnecessary.

Shaft 24 has an eccentric 26- mounted thereto. A horizontal rod 28 is mounted above shaft 24 and slidably supported at each end in appropriate holes 29 in vertical walls 30 of the transmission box. A yoke 32 is suspended at its base from rod 28 and hangs downwardly therefrom so that the arms 34 thereof extend down beyond shaft 24 on either side thereof. A pair of fingers 35, 36 extend inwardly from the arms 34 of yoke 32 to ride against the surface of the eccentric 26. The eccentric 26 is designed for ready removal from shaft 34 for its replacement by other eccentrics having different proportions and sizes and the fingers 35, 36 are adjustable in arms 34 of the yoke to permit a varying of the amount of yoke movement so as to change the width of coils wound. w

Finger 36 constitutes one end of a winding needle shaft 38 which extends outwardly from the transmission box from the same side as and parallel to the drive shaft 18.

A pair of ways 40, here shown to be cylindrical, likewise extend out from the same end of the transmission box below the winding needle shaft 38 and the driving shaft 18 and terminate in a tail stock 42. The tail stock 42 is essentially an open frame member receiving the ends 44 of the ways and slidably and rotatably mounting the remote end 46 of the winding needle shaft 38.

The illustrated form of winding needle consists ,of a sleeve 48adjustable on shaft 38 and locked in position on shaft 38 by set screws 50. The sleeve 48 is contained in an appropriate bore in an upright plate 52. Plate 52 has a pair of transverse bores therein, the lower of which supports the winding needle 54 and the upper of which an arrn 58 carrying an idler pulley guide 60 at its outer end. Set screws 62 secure the needle "56 and arm 58 in the block 52. In the illustrated embodiment the winding needle is simply a relatively small rod or bar having an aperture 64 in the outer end thereof.

The drive shaft 18 is a simple stub shaft. A variety of mandrel sleeves 66 are used in conjunction with a winding machine which are formed at one end to fit over the drive shaft 18 and at the other end to accommodate a variety of mandrels 68 of different diameters to meet the particular coil requirements as to inside diameter. The illustrated sleeve has set screws 69 for securing it to the drive shaft and for securing a mandrel within the other end thereof. The mandrel 68 is thus extended axially outward from the drive shaft 18 and has a free unsupported end 70.

The bore 64 in the winding needle 56 is situated to be substantially vertically above the center line of the mandrel.

In the process of coil winding a coil of wire 72 will be supported to the rear of the coil winding machine and the wire 74 will be fed from coil 72 through, for instance, an acetone bath illustrated diagrammatically at 76, over the idler pulley guide 60, through the eye of the winding needle 56 and onto the mandrel 68.

All of the above described structure is characteristic of a particular universal type coil winding machine commonly used in the coil winding industry. There are other forms of machines and other forms of the various components of the machine. Insofar, however, as coils are formed by wrapping wire about a mandrel, my invention will have application.

The accessory whereby automatic production of discrete coils is achieved consists, in the illustrated embodiment, of a base 78 which may be a relatively heavy metal plate having a pair of transverse grooves 80 on the underside thereof into which the ways 40 are received when the base is situated on the machine. A plate-like clamp 82, proportioned to span the ways, is mounted to the underside of the base 78 by a thumb screw 84 extending upwardly through the center thereof. The thumb screw and. clamp serve to anchor the base to the ways in a particular desired location. A solenoid 86 having an armature 88 is secured to the base longitudinally of the ways.

Turning particularly to FIG. 5, an ejector vise 90 has a bore 92 therein at the lower end thereof by which it is secured to the end of the armature 88 as by a press fit, a set screw, etc. The vise extends upward from bore 92 as'two diverging arms 94 which terminate at their upper ends in facing, concave clamping surfaces 96. A screw 98 extends through an appropriate bore in one of the arms 94 and into a threaded hole 100 in the other of said arms by means of which the arms may be drawn together or be permitted to spring apart. The arms 94 are long enough so that the clamping surfaces thereof center about the mandrel 68. The ejector vise is adapted to hold and operate an ejector 102, between the clamping surfaces 96.

The ejector is a tubular element having an inside bore 104 proportioned to fit slidably on mandrel 68. Exterior-1y, one end 106 of the ejector is proportioned to be received between the clamping surfaces 96 of the vise and to be clamped therein upon tightening of the screw 98. The other end 108 of the ejector has an outside diameter substantially equal to the outside diameter of the coil to be wound.

The ejector vise also carries a needle lifter 110. The

A needle lifter is a member formed of thin plate and includes a lower arm 112 which is secured against arm 94 of the ejector vise by the head of screw 98 to lie flat thereagainst, and a triangular head 114 extending above the vise and ejector 102.

It will be appreciated from FIG. 7 that when the ejector is clamped into the ejector vise the other end extends out to the side of the vise away from the transmission box 12. The head 114 of the needle lifter has a horizontal lower side 116 and sloping upper side 118 which meet at a point 120 extending beyond the ejector 102 on that side thereof away from box 12. The point 120 of the needle lifter head should be near enough the horizontal plane of the mandrel 68 so as to be below the plane of the winding needle even when winding coils of relatively small thickness. The upper side 1 18 of the needle lifter head 114 slopes upward from the point 120 toward box 12 on a line which passes above the outer periphery of the ejector 102.

One end 119 of a tension spring 121 is held under the head of screw 98 and the other end 123 of the spring is hooked into an appropriate bore 125 in the end of the transmission housing so as to tend normally to draw the ejector vise and ejector toward the housing and extend the armature 88 of the solenoid 86 outward.

The solenoid 86 is energized through a lead 122 which extends to one terminal of a normally open micro-switch 124 sceured to the transmission box 12. The other terminal of the micro-switch 126 and the other lead 128 of the solenoid 86 are connected to a source of power.

The back side of the transmission housing 12includes the counter gear train 20 consisting of the gears 130, 132 and 134. Gear 130 is driven by appropriate gearing inside the transmission housing 12 from the input shaft 14. Gear 132 is a replaceable idler and gear 134 is normally used to actuate the counter. Since my invention is directed to the automatic production of coils, a counter has not been illustrated, although one may be present. Gear 134 may have a finger 136 secured thereto which extends out beyond the periphery of the gear 134. The micro-switch includes a switch actuating button 138 extending into the path of movement of the finger 136. The gearing as between gears 130, 132 and 134 is so adjusted that when an appropriate number of turns have been wound on the mandrel, finger 136 will make a full revolution and strike button 138 to close the switch and energize solenoid 86.

The mandrels 68 of universal gear winding machines conventionally are solid rods. I contemplate that the outer free ends 70 of the mandrels to be employed in the practice of my invention be tubular instead and that a mandrel extension 142 having a smaller diameter than the mandrel employed be frictionally fitted into the tubular end 70 of the mandrel to be removably contained therein. The mandrel extension should extend preferably an appreciable distance beyond the end of the mandrel proper.

My device operates as follows: Assuming that a coil of given size is to be wound, an appropriate mandrel is installed on the machine. An eccentric 26 is selected to give the desired degree of oscillation of the winding needle or in other words to determine the length of the coil, and the fingers 35 and 36 are adjusted to bear against it. The gearing 130, 132 and 134 on the back side of the transmission housing is selected to place the desired number of turns on the mandrel. The winding needle is then adjusted by moving sleeve 48 on shaft 38 so that the area of the mandrel on which the coil will be laid is about a coils length away from the free end 70 of the mandrel.

An ejector 102 is selected which has an annular end surface about equal to that of a finished coil, placed on the mandrel and locked in the ejector vise 90. A needle lifter 110 will likewise be secured to the ejector vise, the upper sloping edge 18 of which lies above thetop horizontal tangen plane of the ejector and the point 120 of which will be below the needle 56 as it rests on the outside of a finished coil.

A coil is started manually in conventional fashion, the coil wire feeding through the acetone bath and onto the mandrel, and the winding continues in the usual way, the rapidly evaporating acetone making the wire coating first tacky and then drying so that the coil turns stick together and then set in the laid coil form. When the predetermined number of turns have been placed on the mandrel, finger 136 will revolve to the position where it actuates button 138 of micro-switch 124, closing a circuit to the solenoid 86. The armature 88 is drawn to the right (to the left in FIGS. 9, and 11), and, as will be particularly appreciated from FIGS. 9, 10 and 11, the needle lifter intercepts the underside of the needle 56 initially and begins to rock the needle upwardly about shaft 38 and remove it from the surface of the finished coil (FIG. 10). Upon further movement of the ejector vise 90 the ejector 192 is brought into contact with the edge of the completed coil and displaces it rapidly away from the zone of winding to the very end 70 of the mandrel 68 (FIG. 11) but not off the end of the mandrel. At the end of the stroke of the ejector the circuit to the electro-rnagnet is broken and the spring 121 draws the ejector back to its starting position (FIG. 9) and leaves the winding zone free for the winding of the next coil. The mandrel, during this displacement of the wound coil, has continued to revolve and wire has been drawn from the spool 72 which upon return of the ejector to its non energized position and upon continued rotation of the mandrel will be drawn tight around the mandrel but in separate and detached turns as illustrated at 144. The first wound coil 146, now displaced from its winding position, still rests on the mandrel and fits the mandrel tightly so as to anchor the beginning end of the next coil to be formed to the mandrel in order that the coil will wind and not slip on the mandrel.

The second coil will then be wound conventionally and when the necessary number of turns have been made as determined by finger 136 intercepting button 138, the ejector will move again to displace the second formed coil 148 to the very end of the mandrel which in turn moves the first formed coil off onto the mandrel extension and returns again to permit the winding of a third formed coil, each consecutive coil being connected to the next coil by a pigtail of wire.

The coils as they are completed will build up gradually on the mandrel extension, and when the extension is full or when a desired number of coils have been placed on the extension the string of coils on the extension will be detached and removed from the mandrel extension 142.

I have stated that the zone of winding of the coils should be a coils width displaced from the free end 70 of the mandrel. The minimum requisite of spacing is that the just completed coil be not totally displaced from the mandrel in order that the coil provide the necessary anchoring of the wire to the mandrel to start the second coil and avoid slip of the wire on the mandrel.

In the practice of my invention as above described, my initial impression was that the coil strings produced would require separation into individual coils in order to provide a marketable or usable product. Subsequent experiment and experience, however, demonstrated conclusively the desirability of the coil strings as produced in the practice of my invention over the separated coils and to the best of my knowledge the coil strings resulting from the practice of my invention are a novel and exceedingly useful product and a significant aspect of my invention.

In the assembly of electronic equipment such as radios, television receivers and the like, the assembler normally must grope in a box for a coil to be installed, withdraw the coil from the box and connect its terminals in the required manner. By virtue of the coil strings of my invention a person engaged in assembly may hold an entire string of coils in his hand, connect the free lead of an end coil, sever the wire connecting that coil to the next, connect the other lead and have the next coil immediately at hand with the lead thereof immediately available for the next connection. In practice this has resulted in greatly accelerated assembly work and improved accuracy.

Where an assembly plant does its own coil winding the advantage of my coil strings are particularly apparent. Coil strings of, for instance, ten to twenty coils may be removed from a group of automatic coil winding machines embodying my invention as they are formed and delivered directly to those engaged in assembly. In this way, the assembler is provided with a stock of coil parts not randomly mixed in a box but connected together in order for optimum facility in handling.

It is apparent, however, that in the use of coil strings of this character, the wire interconnecting consecutive coils must be equal in length to the desired lead length on each side of the coils. I have defined above the minimum distance of the zone of winding on the mandrel from the free end 70 thereof. The zone of winding may be displaced a greater distance than the minimum from the free end in order to obtain the desired length of connecting wire. This is accomplished by loosening the set screws 50 and moving the sleeve 48 on the winding needle shaft 38 and resetting the sleeve so as to remove the winding zone a greater distance from the mandrel end. The potential movement of the ejector 102, or in other words, the stroke of the solenoid 86 should be great enough to permit a substantial variation in the amount of displace ment of a finished coil from the winding zone on the mandrel to its displaced position at the free end thereof. In this fashion the length of wire strands interconnecting consecutive coils can be accurately determined and varied to meet different lead requirements.

A further advantage results from this accurate spacing of coils in a string in that lead lengths are often critical in electronic assemblies. Under conventional Winding procedures accurate lengths of lead are difiicult to establish and subsequent trimming may sometimes be required. By virtue of my invention wherein coils are accurately spaced a distance equal to the total desired lead lengths of a coil, the need for accurate manual determination of lead length or, alternatively, subsequent trimming is entirely avoided.

It will be evident from the foregoing description that I have devised a method for the automatic production of coils on conventional coil winding machines which results in an enormous saving of labor and supervisory attention. By the use of my invention I have found that a single operator can operate many coil winding machines whereas in conventional practice it has been necessary to provide an operator for each machine. My method likewise provides for a far more rapid production of coils in that under conventional practice each coil must be manually started and terminated, stopping the coil Winding machine in the process, Whereas by virtue of my method each coil is started and terminated automatically and the coil winding machine is in continuous operation throughout the process of making the coils.

It will likewise be appreciated that I have devised mechanism well suited to the achievement of this method whereby coils are automatically produced in simple, effective and certain fashion.

I have further found that the coil strings as produced in the practice of my invention have substantial advantage over the individually separate coils resulting from conventional coil winding procedures and facilitate greatly speed and accuracy in assembly work.

It will be evident from the foregoing that my novel method, apparatus and product have been described in relation to a particular process practiced by means of particular apparatus on a particular machine and that many alternative practices in following my method or alternative structure in my mechanism are conceivable and within the purview of my invention, and I therefore desire that my invention be regarded as being limited only as set forth in the following claims.

I claim:

1. A method of making electric coils which comprises continuously treating coil wire to make the coating thereof temporarily cohesive, winding said wire on a pre-determined area of a continuously rotating, free-ended cylindrical mandrel to effect cohesive contact between the turns of wire in said area to form a coherent coil, said area being spaced from said free end, counting automatically the turns in said coil to a pre-determined number, advancing an ejector against said coil upon arrival at said number to displace said coil toward the free end of said mandrel substantially beyond said area at a rate to space consecutive turns formed during said displacement from each other, said displacement being insufiicient to move said coil entirely oif said mandrel, and withdrawing said ejector to permit a second coil to build in said area, the cohesion of the turns of said coil serving to anchor the wire relative to the mandrel to start said second coil.

2. In a coil winding machine including a rotating mandrel having a free end, a winding needle for laying Wire on a predetermined coil winding area of said mandrel and mechanism for counting mandrel revolutions, a coil ejector movable axially relative to said mandrel from a position away from said coil winding area through said coil winding area toward said free end of said mandrel and having a face engageable with an end of a coil formed in said coil winding area to displace said coil from said area upon said movement, a needle lifter associated with said ejector to be movable therewith and having a sloping surface to move said needle out of the path of said ejector prior to said movement of said ejector into said Winding References Cited in the file of this patent UNITED STATES PATENTS 862,935 Pfanstiehl Aug. 13, 1907 2,030,988 Hofstetter Feb. 18, 1936 2,122,468 Hill July 5, 1938 2,351,604 Ferrill June 20, 1944 2,380,320 La France July 10, 1945 2,388,598 Cahill Nov. 6, 1945 2,441,804 Parry May 18, 1948 2,724,415 Orth Nov. 22, 1955 2,736,346 Ammann Feb. 28, 1956 2,739,371 Grisdale et al. May 27, 1956 2,780,246 Steger Feb. 5, 1957 2,848,794 Roth Aug. 26, 1958 2,863,612 Sherwin Dec. 9, 1958 3,003,525 Fuller Oct. 10, 1961 FOREIGN PATENTS 50,369 Austria June 1, 1911 

2. IN A COIL WINDING MACHINE INCLUDING A ROTATING MANDREL HAVING A FREE END, A WINDING NEEDLE FOR LAYING WIRE ON A PREDETERMINED COIL WINDING AREA OF SAID MANDREL AND MECHANISM FOR COUNTING MANDREL REVOLUTIONS, A COIL EJECTOR MOVABLE AXIALLY RELATIVE TO SAID MANDREL FROM A POSITION AWAY FROM SAID COIL WINDING AREA THROUGH SAID COIL WINDING AREA TOWARD SAID FREE END OF SAID MANDREL AND HAVING A FACE ENGAGEABLE WITH AN END OF A COIL FORMED IN SAID COIL WINDING AREA TO DISPLACE SAID COIL FROM SAID AREA UPON SAID MOVEMENT, A NEEDLE LIFTER ASSOCIATED WITH SAID EJECTOR TO BE MOVABLE THEREWITH AND HAVING A SLOPING SURFACE TO MOVE SAID NEEDLE OUT OF THE PATH OF SAID EJECTOR PRIOR TO SAID MOVEMENT OF SAID EJECTOR INTO SAID WINDING AREA, AND MEANS FOR MOVING AND RETURNING SAID EJECTOR UPON SAID REVOLUTION COUNTING MECHANISM COUNTING A PREDETERMINED NUMBER OF TURNS. 